Make the error message more meaningful

For table test1 (C1 varchar (10), C2 varchar (10)), when I insert a row using

sqlContext.sql("insert into test1 values ('abc', 'def', 1)")

I got error message

Exception in thread "main" java.lang.RuntimeException: RelationC1#0,C2#1 JDBCRelation(test1)
requires that the query in the SELECT clause of the INSERT INTO/OVERWRITE statement generates the same number of columns as its schema.

The error message is a little confusing. In my simple insert statement, it doesn't have a SELECT clause.

I will change the error message to a more general one

Exception in thread "main" java.lang.RuntimeException: RelationC1#0,C2#1 JDBCRelation(test1)
requires that the data to be inserted have the same number of columns as the target table.